1. Field of the Invention
This invention relates to a method of building an underground structure, and more particularly to a method of building an underground structure composed of vertical corner columns and vertical concrete columns provided between the corner columns, and concrete panels fitted between adjacent columns. The concrete panels are moved downward while digging the ground under them.
2. Description of the Related Art
In the related art, an underground structure is usually built in the following manner. Concrete columns are vertically installed in a dug area of a ground at positions corresponding to corners and intermediate portions of the underground structure to be built. Concrete panels are fitted between the columns while digging the ground under them to a predetermined depth. The side edges of the concrete panels are joined to the columns using bolts or the like. The bottom of the underground structure is made by applying concrete to a space defined by the concrete panels. (Refer to Japanese Patent No. 282954.)